fix: update gssmr genesis to use pallet_babe::SameAuthoritiesForever (ChainSafe#1696)

Author: noot

chain/gssmr/genesis-spec.json

@@ -92,7 +92,7 @@ func TestInstance_BabeConfiguration_NodeRuntime_WithAuthorities(t *testing.T) {
 		SlotDuration:       3000,
 		EpochLength:        200,
 		C1:                 1,
-		C2:                 4,
+		C2:                 2,
 		GenesisAuthorities: expectedAuthData,
 		Randomness:         [32]byte{},
 		SecondarySlots:     1,